use cases that require the functionality of reaching distributed consensus on what should be added, removed, stored on that DB. in blockchains, how consensus i

use cases that require the functionality of reaching distributed consensus on what should be added, removed, stored on that DB. in blockchains, how consensus is reached is also formalized so that there is a verifiable and distributed audit trail for every user. blockchains also automatically backup everything in a more distributed fashion, allow for higher participation, enable incentive mechanism experimentation, tokenization, useful ZK-proofs... all without the NEED to trust trust a centralized DB. if it doesn't have any of the above features, then a reason for using a centralized, private blockchain is to more easily distribute/decentralize that consensus-reaching DB in the future. ... also, blockchains aren't immutable if the consensus agrees to change something inherent in the protocol. this happens with every hard fork.